Sheet metal scribing tool



March 1958 J. P. PATTERSON ETAL SHEET METAL SCRIBING TOOL Filed June 5,1956 m 0 mm, m P d W JH Fig.3.

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United States Patent 2,827,703 SHEET METAL SCRBING TQUL John P.Patterson and Floyd @Clemons, Tallahassee, Fla. Application .l'nne 5,1956, Serial No. 589,439 2 (Jlairns. ((Zl. 3344) The present inventionrelates to a special purpose hand tool which is expressly constructedand novelly designed to serve the requirements of a sheet metal workeror other user in scribing, marking, and denoting fold lines when layingout a sheet metal blank which is to be subsequently transformed into anauxiliary duct connectible with a primary duct or so-called trunk-line.

Stated otherwise, the invention pertains to a simple, expedient andpractical hand tool susceptible of ready usefulness in sheet metal workin the laying out of patterns. That is to say, by the use of this toolit is possible to scribe or mark three lines on a sheet metal blank atthe same time and in one operation. In this connection it is to bepointed out that it was the current practice, prior to the advent of theimproved tool, to mark off three spaces with a ruler adjacent to themarginal edge of the blank which was being used. Then one draws orpencils the lines with the aid of a straightedge. This may be said to bethe standard lay out practice in the procedure of providing either aprefabricated or an on-the-job so-called tap-in, that is, theaforementioned auxiliary duct with its end flanged so that it can beconnected with an opening tapped in one of the side walls of thetrunk-line.

An object of the invention is to provide a scribing or marking toolwhich greatly expedites the steps which may now be pursued resulting ina great saving in time, labor and money.

Other objects, features and advantages will become more readily apparentfrom the following description and the accompanying sheet ofillustrative drawings.

In the drawings:

Fig. 1 is a perspective view of the improved scribing tool;

Fig. 2 is a fragmentary plan View of an end portion of the blank whichis being, or has been, scribed after having used the scribing tool (atthe right) here depicted;

Fig. 3 is a view in plan based on Fig. 2 and showing what the blanklooks like after the marked edge has been notched or cut out to definebendable flaps; and

Fig. 4 is a sectional view showing the main duct or trunk-line and theauxiliary tap-in connected to the apertured wall thereof in a well-knownmanner Referring first to Fig. 4 the trunk-line or main duct is denotedby the numeral 6 and has a tapped opening or hole in one side wall as at8 with which the auxiliary duct or so-called tap-in 10 is connected. Thetap-in is provided at its connectible end with the usual cooperatingseveral flanges 12, 14 and 16. These require the provision of fold ormarker lines to provide the required bends 18. Fig. 2 shows the blankand Fig. 3 the next step wherein it has been notched to provide theflaps 20. The blank is also folded along the lengthwise lines 22 toprovide the construction shown in Fig. 4

The idea here is centered on the hand tool and this comprises ablock-like body 24 preferably rectangular and having a flat side 26carrying rigid laterally projecting spaced parallel prongs 28 havingcoplanar needle-like terminals or scribing ends 30. These, when properlyraked or moved across the surface of the blank 32, seen in Fig. 2,provide the scribed lines 34, 36 and 38 in measured spaced parallelrelationship. To the right there is an integral cylindrical rigidabutment finger 40 having a laterally directed bend or hook 42 whichassists in retaining the tool in position while it is moved along theedge 44 in an obvious manner.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling Within the scope of the invention asclaimed.

What is claimed as new is as follows:

i. For use by a sheet metal worker or one engaged in scribing and layingout a sheet metal blank which is to be subsequently transformed bybending and forming into a duct having a specially flanged end and whichis to be tapped into an opening provided therefor in a trunkiiue; ameasuring and scribing hand tool comprising a body functioning as ahandle and having a plurality of rigid duplicate spaced parallelneedle-like scribing prongs projecting laterally from one surface of thebody and which cooperatively function in unison and in a manner to scoreand visibly mark the surface of the blank with spaced parallelflange-forming fold-lines, and a guiding abutment integral with andprojecting laterally from said one surface, said abutment comprising astout rigid finger spaced from and paralleling an adjacent one of saidprongs, said finger being adapted to abut and ride slidingly along anedge of said blank, and terminating at its outer end in a lateral bendfunctioning as a hook, all of said prongs being the same in length andhave their pointed scribing ends disposed in a common plane, said fingerand hook being cylindrical in cross-section, said hook being directedtoward the pointed ends of the prongs and being parallel to the handleand also at right angles to the axis of the finger, and the convexsurface of the hook which is closest to and faces said one side of saidhandle being in substantially the same plane as the aforementionedcommon plane of said prongs so that it contacts one surface of the sheetmetal blank while the pointed ends of the prongs ride against and scorethe other surface of said blank.

2. For use by sheet metal workers or one engaged in scribing and layingout an edge portion of a sheet metal blank to assist one in preparingand bending the scribed portion into an especially flanged end which isadapted to be tapped into an opening provided therefor in a trunk line;a measuring and scribing hand tool comprising a substantiallyrectangular block-like body having at least one fiat side, an abutmentfinger having one end attached to said flat side and extending at rightangles therefrom and terminating at the outer end in a hook, said hookbeing adapted to slidingly contact one surface of the sheet metal blank,and the portion of the finger adjacent to the hook being adapted to abutand ride along the very edge of the blank, said finger being cylindricalin cross section, and a plurality of rigid duplicate spaced parallelneedle-like scribing prongs having corresponding ends attached to andprojecting laterally from said one surface of the body, said prongsbeing in a plane which is common to all the prongs and also common tothe plane of said finger, the free ends of said prongs all being pointedand terminating in a plane with each other and also in substantially theplane occupied by the surface of the hook which contacts the sheet metalblank when in use.

References Cited in the file of this patent UNITED STATES PATENTS509,356 Bechmann Nov. 28, 1893 1,697,756 Curran Jan. 1, 1929 2,016,545Dickerson Oct. 8, 1935 FOREIGN PATENTS 397,771 France Mar. 6, 1909

